The long-term administration of delta-9-THC, the primary psychoactive compound in marijuana, is associated with decreased mortality in monkeys infected with the simian immunodeficiency virus (SIV), a primate model of HIV (human immunodeficiency virus) disease, according to in vivo experimental trial data published in the June issue of the journal AIDS Research and Human Retroviruses.

Investigators at the Louisiana State University Health Sciences Center assessed the impact of chronic intramuscular THC administration compared to placebo on immune and metabolic indicators of SIV disease during the initial six-month phase of infection.

Researchers reported, “Contrary to what we expected, … delta-9-THC treatment clearly did not increase disease progression, and indeed resulted in generalized attenuation of classic markers of SIV disease.” Authors also reported that THC administration was associated with “decreased early mortality from SIV infection” and “retention of body mass.”